Question: Michael is 4 times as old as Ben and is also 24 years older than Ben. How old is Ben?
Explanation: We can use the given information to write down two equations that describe the ages of Michael and Ben. Let Michael's current age be $m$ and Ben's current age be $b$ $m = 4b$ $m = b + 24$ Now we have two independent equations, and we can solve for our two unknowns. Since we are looking for $b$ , and both of our equations have $m$ alone on one side, this is a convenient time to use elimination. Subtracting the second equation from the first equation, we get: $0 =$ $4b$ $-$ $ (b + 24)$ which combines the information about $b$ from both of our original equations. Solving for $b$ , we get: $3 b = 24$ $b = 8$.